add ability to download tx meter values as csv

Author: goekay

pom.xml

@@ -532,6 +532,10 @@
             <groupId>com.fasterxml.jackson.core</groupId>
             <artifactId>jackson-annotations</artifactId>
         </dependency>
+        <dependency>
+            <groupId>tools.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-csv</artifactId>
+        </dependency>
         <!-- Needed for Joda fields in de.rwth.idsg.steve.web.api -->
         <dependency>
             <groupId>tools.jackson.datatype</groupId>

src/main/java/de/rwth/idsg/steve/repository/dto/TransactionDetails.java

@@ -19,6 +19,7 @@
 package de.rwth.idsg.steve.repository.dto;
 
 import com.fasterxml.jackson.annotation.JsonIgnore;
+import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 import jooq.steve.db.tables.records.TransactionStartRecord;
 import lombok.Builder;
 import lombok.Getter;
@@ -46,6 +47,16 @@ public class TransactionDetails {
     @JsonIgnore
     private final TransactionStartRecord nextTransactionStart;
 
+    @JsonPropertyOrder(value = {
+        "valueTimestamp",
+        "value",
+        "readingContext",
+        "format",
+        "measurand",
+        "location",
+        "unit",
+        "phase"
+    })
     @Getter
     @Builder
     public static class MeterValues {

src/main/java/de/rwth/idsg/steve/service/TransactionService.java

@@ -36,6 +36,8 @@
 import org.joda.time.DateTime;
 import org.springframework.stereotype.Service;
 import org.springframework.util.CollectionUtils;
+import tools.jackson.dataformat.csv.CsvMapper;
+import tools.jackson.dataformat.csv.CsvSchema;
 
 import java.io.Writer;
 import java.util.Comparator;
@@ -56,6 +58,11 @@ public class TransactionService {
     private final TransactionRepository transactionRepository;
     private final OcppServerRepository ocppServerRepository;
 
+    private final CsvMapper csvMapper = CsvMapper.builder().findAndAddModules().build();
+    private final CsvSchema schema = csvMapper.schemaFor(TransactionDetails.MeterValues.class)
+        .withHeader()
+        .withNullValue("\"\""); // to be consistent with JOOQ's CSV behavior
+
     public List<Transaction> getTransactions(TransactionQueryForm form) {
         return transactionRepository.getTransactions(form);
     }
@@ -64,6 +71,12 @@ public void writeTransactionsCSV(TransactionQueryForm form, Writer writer) {
         transactionRepository.writeTransactionsCSV(form, writer);
     }
 
+    public void writeTransactionMeterValuesCSV(int transactionPk, Writer writer) {
+        try (var seqWriter = csvMapper.writer(schema).writeValues(writer)) {
+            seqWriter.writeAll(getDetails(transactionPk).getValues());
+        }
+    }
+
     public List<Integer> getActiveTransactionIds(String chargeBoxId) {
         return transactionRepository.getActiveTransactionIds(chargeBoxId);
     }

src/main/java/de/rwth/idsg/steve/web/controller/TransactionsReservationsController.java

@@ -64,6 +64,7 @@ public class TransactionsReservationsController {
     private static final String TRANSACTIONS_PATH = "/transactions";
     private static final String TRANSACTION_STOP_PATH = "/transactions/stop/{transactionPk}";
     private static final String TRANSACTIONS_DETAILS_PATH = "/transactions/details/{transactionPk}";
+    private static final String TRANSACTIONS_DETAILS_METER_VALUES_CSV_PATH = TRANSACTIONS_DETAILS_PATH + "/meterValues.csv";
     private static final String TRANSACTIONS_QUERY_PATH = "/transactions/query";
     private static final String RESERVATIONS_PATH = "/reservations";
     private static final String RESERVATIONS_QUERY_PATH = "/reservations/query";
@@ -94,6 +95,17 @@ public String getTransactionDetails(@PathVariable("transactionPk") int transacti
         return "data-man/transactionDetails";
     }
 
+    @RequestMapping(value = TRANSACTIONS_DETAILS_METER_VALUES_CSV_PATH)
+    public void getTransactionDetailsMeterValuesCsv(@PathVariable("transactionPk") int transactionPk,
+                                                    HttpServletResponse response) throws IOException {
+        String fileName = "transaction_%s_meter_values.csv".formatted(transactionPk);
+        String headerKey = "Content-Disposition";
+        String headerValue = "attachment; filename=\"%s\"".formatted(fileName);
+        response.setContentType("text/csv");
+        response.setHeader(headerKey, headerValue);
+        transactionService.writeTransactionMeterValuesCSV(transactionPk, response.getWriter());
+    }
+
     @RequestMapping(value = TRANSACTIONS_QUERY_PATH)
     public String getTransactionsQuery(@Valid @ModelAttribute(PARAMS) TransactionQueryForm params,
                                        BindingResult result, Model model,

src/main/webapp/WEB-INF/views/data-man/transactionDetails.jsp

@@ -43,6 +43,10 @@
     </center>
     <br>
     <section><span>Intermediate Meter Values</span></section>
+    <form action="${ctxPath}/manager/transactions/details/${details.transaction.id}/meterValues.csv" method="get">
+        <input type="submit" value="Download CSV">
+    </form>
+    <br>
     <table class="res">
         <thead>
         <tr>